Remove the unused legacy remote compaction implementation (#44273)

## Why

Remote compaction already uses the normal Responses API, leaving the legacy `/responses/compact` runner unused.

## What changed

- Remove the legacy runner, endpoint client, request types, analytics variant, and obsolete test helpers and snapshots.
- Move tool-output trimming and its metadata tests into `compact_remote_history` for reuse by remote compaction v2.
- Consolidate retained-history filtering in the v2 implementation and remove redundant `RemoteCompactionV2` settings from tests.

## Testing

Extend the retained-history unit test to explicitly check that hook prompts survive compaction.

GitOrigin-RevId: 999bb1391aa22c3c281d6a96f98817d6c9e46ed9

codex-rs/codex-api/src/common.rs

@@ -43,28 +43,6 @@ impl From<CyberAccessProgram> for AccessPrograms {
     }
 }
 
-/// Canonical input payload for the compaction endpoint.
-#[derive(Debug, Clone, Serialize)]
-pub struct CompactionInput<'a> {
-    pub model: &'a str,
-    pub input: &'a [ResponseItem],
-    #[serde(skip_serializing_if = "str::is_empty")]
-    pub instructions: &'a str,
-    #[serde(skip_serializing_if = "Option::is_none")]
-    pub tools: Option<ResponsesApiTools>,
-    pub parallel_tool_calls: bool,
-    #[serde(skip_serializing_if = "Option::is_none")]
-    pub reasoning: Option<Reasoning>,
-    #[serde(skip_serializing_if = "Option::is_none")]
-    pub service_tier: Option<&'a str>,
-    #[serde(skip_serializing_if = "Option::is_none")]
-    pub prompt_cache_key: Option<&'a str>,
-    #[serde(skip_serializing_if = "Option::is_none")]
-    pub text: Option<TextControls>,
-    #[serde(skip_serializing_if = "Option::is_none")]
-    pub access_programs: Option<AccessPrograms>,
-}
-
 /// Canonical input payload for the memory summarize endpoint.
 #[derive(Debug, Clone, Serialize)]
 pub struct MemorySummarizeInput {

codex-rs/codex-api/src/endpoint/compact.rs

@@ -1,115 +0,0 @@
-use crate::auth::SharedAuthProvider;
-use crate::common::CompactionInput;
-use crate::endpoint::session::EndpointSession;
-use crate::error::ApiError;
-use crate::provider::Provider;
-use codex_client::HttpTransport;
-use codex_client::RequestTelemetry;
-use codex_protocol::models::ResponseItem;
-use http::HeaderMap;
-use http::Method;
-use serde::Deserialize;
-use std::sync::Arc;
-use std::sync::OnceLock;
-use std::time::Duration;
-
-const X_CODEX_TURN_STATE_HEADER: &str = "x-codex-turn-state";
-
-pub struct CompactClient<T: HttpTransport> {
-    session: EndpointSession<T>,
-}
-
-impl<T: HttpTransport> CompactClient<T> {
-    pub fn new(transport: T, provider: Provider, auth: SharedAuthProvider) -> Self {
-        Self {
-            session: EndpointSession::new(transport, provider, auth),
-        }
-    }
-
-    pub fn with_telemetry(self, request: Option<Arc<dyn RequestTelemetry>>) -> Self {
-        Self {
-            session: self.session.with_request_telemetry(request),
-        }
-    }
-
-    fn path() -> &'static str {
-        "responses/compact"
-    }
-
-    pub async fn compact(
-        &self,
-        body: serde_json::Value,
-        extra_headers: HeaderMap,
-        request_timeout: Duration,
-        turn_state: Option<&OnceLock<String>>,
-    ) -> Result<Vec<ResponseItem>, ApiError> {
-        let resp = self
-            .session
-            .execute_with(
-                Method::POST,
-                Self::path(),
-                extra_headers,
-                Some(body),
-                |req| {
-                    req.timeout = Some(request_timeout);
-                },
-            )
-            .await?;
-        if let Some(turn_state) = turn_state
-            && let Some(header_value) = resp
-                .headers
-                .get(X_CODEX_TURN_STATE_HEADER)
-                .and_then(|value| value.to_str().ok())
-        {
-            let _ = turn_state.set(header_value.to_string());
-        }
-        let parsed: CompactHistoryResponse =
-            serde_json::from_slice(&resp.body).map_err(|e| ApiError::Stream(e.to_string()))?;
-        Ok(parsed.output)
-    }
-
-    pub async fn compact_input(
-        &self,
-        input: &CompactionInput<'_>,
-        extra_headers: HeaderMap,
-        request_timeout: Duration,
-        turn_state: Option<&OnceLock<String>>,
-    ) -> Result<Vec<ResponseItem>, ApiError> {
-        let body = serde_json::to_value(input)
-            .map_err(|e| ApiError::Stream(format!("failed to encode compaction input: {e}")))?;
-        self.compact(body, extra_headers, request_timeout, turn_state)
-            .await
-    }
-}
-
-#[derive(Debug, Deserialize)]
-struct CompactHistoryResponse {
-    output: Vec<ResponseItem>,
-}
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-    use codex_client::Request;
-    use codex_client::Response;
-    use codex_client::StreamResponse;
-    use codex_client::TransportError;
-
-    #[derive(Clone, Default)]
-    struct DummyTransport;
-
-    impl HttpTransport for DummyTransport {
-        async fn execute(&self, _req: Request) -> Result<Response, TransportError> {
-            Err(TransportError::Build("execute should not run".to_string()))
-        }
-
-        async fn stream(&self, _req: Request) -> Result<StreamResponse, TransportError> {
-            Err(TransportError::Build("stream should not run".to_string()))
-        }
-    }
-
-    #[test]
-    fn path_is_responses_compact() {
-        assert_eq!(CompactClient::<DummyTransport>::path(), "responses/compact");
-    }
-}

codex-rs/codex-api/src/endpoint/mod.rs

@@ -1,4 +1,3 @@
-pub(crate) mod compact;
 pub(crate) mod images;
 pub(crate) mod memories;
 pub(crate) mod models;
@@ -9,7 +8,6 @@ pub(crate) mod responses_websocket;
 pub(crate) mod search;
 mod session;
 
-pub use compact::CompactClient;
 pub use images::ImagesClient;
 pub use memories::MemoriesClient;
 pub use models::ModelsClient;

codex-rs/codex-api/src/lib.rs

@@ -28,7 +28,6 @@ pub use crate::auth::AuthProviderFuture;
 pub use crate::auth::SharedAuthProvider;
 pub use crate::auth::auth_header_telemetry;
 pub use crate::common::AccessPrograms;
-pub use crate::common::CompactionInput;
 pub use crate::common::MemorySummarizeInput;
 pub use crate::common::MemorySummarizeOutput;
 pub use crate::common::OpenAiVerbosity;
@@ -50,7 +49,6 @@ pub use crate::common::WS_REQUEST_HEADER_TRACEPARENT_CLIENT_METADATA_KEY;
 pub use crate::common::WS_REQUEST_HEADER_TRACESTATE_CLIENT_METADATA_KEY;
 pub use crate::common::create_text_param_for_request;
 pub use crate::common::response_create_client_metadata;
-pub use crate::endpoint::CompactClient;
 pub use crate::endpoint::ImagesClient;
 pub use crate::endpoint::MemoriesClient;
 pub use crate::endpoint::ModelsClient;